A ruthenium oxide-supported material is useful as a catalyst for use in production of chlorine by oxidizing hydrogen chloride with oxygen. For example, U.S. Pat. No. 5,871,707 discloses a process for producing a ruthenium oxide-supported material, and this process comprises the steps of allowing a carrier to support a ruthenium compound, specifically a titanium oxide or a composite oxide of titanium oxide and zirconium oxide, and then calcining it in an air.
U.S. Pat. No. 6,852,667 discloses a process for producing a ruthenium oxide-supported material, and this process comprises the steps of allowing a titanium oxide carrier to support a ruthenium compound thereon, reducing the ruthenium compound on the carrier, with hydrazine, sodium borohydride or the like, and oxidizing it, or specifically calcining it in an air. WO01/10550 discloses a process for producing a ruthenium oxide-supported material, and this process comprises the steps of allowing a titanium oxide carrier to support a ruthenium compound thereon, calcining the ruthenium compound on the carrier, and treating it with hydrazine, and oxidizing it, or specifically calcining it in an air.
Further, JP-A-2002-292279 and JP-A-2004-074073 disclose processes for producing ruthenium oxide-supported materials, and each process comprises the steps of allowing a titanium oxide carrier to support a ruthenium compound thereon, calcining the ruthenium compound on the carrier, allowing it to support thereon a silicon compound such as an alkoxysilane compound or a siloxane compound, and oxidizing it, or specifically calcining it in an air.